Alkylation of isoparaffins



June 13, 1944.

Filed my 12, 1941 A. vooRHlEs, JR., ETAL LKYLATION OF'ISOPARAFFINS 2 Sheets-Shet 1 [NIT/Al. ALKrLA-riau 1 zoals TH YL ENA ALK YL A flor( I IVTNE l June 13, 1944. A. vooRHis, JR., HAL 2,351,464

ALKYLATION OF ISOPARAFFINS hydrocarbons.

yPatented June 13, 1944 este ' Alexis Voor-nies, Jr., and Erwin MI. Hatton, Baton Rouge, La., assignors' to Standard (Dil Development Company, a corporation of Delaware Application .Fuly 12,' wel, Serial No. @21M 4i Claims.

The present invention is concerned with rening of mineral oils and is particularly concerned with the production of hydrocarbon constituents boiling in the motor fuel and the aviation fuel boiling ranges from relatively low boiling hydrocarbon constituents. In accordance with the present process, relatively low boiling olens, particularly ethylene, are alkyiated with isoparainic constituents employing a. mineral acid catalyst. In accordance with the present invention the alkylation is carried out under conditions in which the alkylatmg catalyst intermittently contacts a 4feed stool: comprising ethylene under alkylating conditions.

It is well known in the art to react relatively low boiling oleflns such as olens containing from 2 to 5 carbon atoms in the molecule with saturated hydrocarbons containing a, tertiary carbon atom hereinafter referred to as tertiary These reactions. are generally conducted by employing a feed stock. containing olens and saturated hydrocarbons containing tertiary carbon atoms and contacting the same under slntable conditions with a r.so-called alkylating catalyst. In general, theoperation is conducted under conditions Ain. which the mol ratio of the tertiary hydrocarbons to the olens is relatively high. Temperature and pressure conditions vary considerably. Forexample, the

-alkylating temperature may range from about 29 F. or lower. to temperatures as high as 400 (Gl. 26o-683.4)

the acid was materially lowered indicating an' appreciable acid consumption. We have, however, now discovered that, providedan interroittent treatment be employed with respect to the ethylene and acid, unexpected desirable results are secured. For example, we have discovered that if the acid be employed for alkylation of oleins comprising ethylene in an initial stage and the acid segregated fromthe initial stage, it may be then readily employed -for the alkylation of olens free/of ethylene in a secondary stage without incurring any substantial acid consumption as measured by titratable acidity. is a matter of fact, when operating in this manner the acid is apparently regenerated and the adverse eil'ects of the ethylene removed in the secondary. stage. The process of our invention may be readily understood by reference to the attached drawings( alkylation zone. Referring specically to Figure 1 it is assumed that the alkylation catalyst F. or higher. vHowever, in. general the alkylating temperatures are in the range from about 20 F. to about 10 F. substances may be employed as alkylating catalysts such as aluminum chloride and the like,

the preferred materials comprise mineral acids.

particularly sulfuric acids, having a concentration in the range from about 88% to 100%.

Although these reactions have been entirely satisfactory in operations involving the reaction of olens containing 3 and more carbon.'

atoms in the molecule, they have not been satis- Although a number of factory' for the alkylation of ethylene due to I excessive acid consumption. Heretoiore it has been found thatv 'in a reaction involving the clkylation of ethylene the titratable acidity or of jets 6 or equivalent means. .Temperatureand pressure conditions as well as time o! ccntact in the initial alkylation -zone 5 are adapted -tov secure the maximum yield of the desired A A- product. The reaction mixture of acid emulsion is removed from alkylation zone 5 by means of line 1. A portion of the acid emulsion is segregated from the main emulsion stream by means of line 8 and passed into separation zone 9. The main emulsion stream is recycled to allegiation zone 5 by means of line III through jets Ii.l

The portionof the emulsion stream passed to separation zone 9 separates into a hydrocarbon layer which is removed by means of line II and into an acid layer which is removed by means of line I2. The hydrocarbon layer is passed successively into distillation zones I3, I4, and I5 by means of lines I 5 and I1. Temperature and pressure conditions are adjusted in zone I3 to remove overhead by means of line I8 isobutane which is preferably recycled to initial alkylation zone. Temperature and pressure conditions in zone I4 are adjusted to remove overhead 'by means of line I9 any normal butane constituents factory mixing of the respective 'streams is seis introduced into the system by means of line 50, while the acidris introduced lby means of line 5I, and the stream comprising isobutane by to zone means of line 52. This mixture is introduced into alkylation zone 53 by means of jets 54 or equivalent means. Conditions in zone 53 are adjusted to secure the desired degree of alkylation. 'I'he acid emulsion is removed by means of line 55 and a small portion segregated by means of line 56 and passed to separation zone 51. The remainder of the acid emulsion is recycled to the initial alkylation zone by-means of line 58. The emulsion passed to zone 51 separates into a hydrocarbon fraction which is removed by means of line 59 and into an acid layer which is removed by means of line 50. The hydrocarbon layer is passed serially through distillation zones 8|, 62, 63 and handled in a manner similar to that described above. Isobutane is removed from zone BI by means of line 64 and preferably recycled 53. Normal butane is removed from zone 82 by means of line 65 and handled as desired. 'I'he desired alkylate is removed from zone 63 by means of line 66 whilev the heavy alleviate is removed vby means of line 61. Spent acid maybe withdrawn from the system by means of line 68 while fresh acid is introduced by means of line 5I:

In accordance with our invention, ethylene is intermittently introduced into the system by means of line 10. For operating in this manner cured by passing the mixture through jets orl equivalent means 25. Temperatures, as well as the time of contact are adjusted to secure the maximum yield of the desired product. 'I'he acid emulsion is removed from alkylation zone 22 by means of line 28l and a small portion segregated lby means of line 21 and passed to separation zone 28. The remainder of the emulsion is recycled to the secondary alkylation zone by means of line 29. In zone -28' a separation occurs between the hydrocarbon product and the acid. The

overhead by means of line 31. The total `alkylate product isfractionated in zone 33 to remove overhead by means of line 38, the desired aviation fraction, and to remove 'by means of line 39 the heavy alkylate which may be disposed of in any manner desired.v

In accordance with our invention, the acid layer removed from zone 28 by means of linel 4'0 is recycled to initial alkylation zone 5. Under certain conditions-a portion of this acid may be withdrawn from the system by means of line 4I, regenerated in regeneration zone 42 and re turned to the system by means of line 43. Totally spent acid may be withdrawn from the system by means of line 44, while fresh acid is introduced by means of line 45.

Referring speciilcally to Figure 2, -an oleiin stream comprisingbutylene and higher oleiins over a portion of the cycle the feed to the alkylation zone comprises ethylene while over the remainder of the cycle the feed'. to the alkylation zone is free of ethylene.

It is to lbe understood that the process of the present invention may be widely varied. The respective'zones may comprise any suitable number and arrangement of units. 'I'he invention essentially comprises alternately contacting the alkylated catalyst with a feed stream comprising ethylene and then contacting the catalyst with a feed stream free of ethylene. For operating in this manner, excessive catalyst degradal comprising essentially hydrocarbon constituentscontain 4 or more carbon atoms in the molecule.

Any conventional alkylating conditions may be used in the present invention. 'I'he invention. however, is particularly adapted to operations in which the alkylating catalyst comprises a mineral acid catalyst such as sulfuric acid, fluorosulfonic acid or the like. It is particularly suit able in operations wherein the catalyst comprises a sulfuric acid having a concentration in the range from about 88 to about 100%.`

In order to further illustrate our invention the following examples are given which should not be construed as limiting the same in any manner whatsoever:

Example 1 .A number of alkylation operationswere'conducted in whichin the initial stage the feed comlapparent; that by operating as' described in the stage 1.

prised ethylene and in which in the secondary stage the 'feed was free of ethylene. The results of these operations were as follows:

-From the above it is apperent that unexpected improvements are to be secured with respect to acid conusmption by Operating as described.

Operation 1 Operation 2 Stage i. Stage 2 Stage 1 Stage 2 Catalyst H3804... 'Acid from 07% HISOI.. Acid from m80 1- stage 1. rma {mzyam'm n me nigm'" s :yi

n n ne-- u nem. u ene. Isobutane... Isotm Isolmtane... Isobutane.

Mol ratio: isobntangoiedn. 5. 8 5. 6 5. 5 0. 4 Moi ratio: OnHi/O 2. 2 0 2. 0 0 Total reaction time -minntea-. 12J 120 120 120 mperatuxe 70 70 70 la Product (G|+)= Wt. percent yield on 043| 210 18a 24o 170 Voi. pement l (50-105 'l'. 1.6 5. 1 4. 5 4. I Vol. percent 0| (105-105 F. 21.9' 6. 2 23. 2 5. 0 Voi. percent O 1 (105-180 1. 1.2 1. 3 1. 2 l. 2 Voi. percent 0| (18o-205 F.) 08. 8 80.7 05. 1 80.0 vol. percent Ori-( &9 F 1.o a 1 5.4 a 2 Octane No. A. B. T. M.) ros.. V1.0 93.9 04.7 04.2 Used acid titrata le acidity percent-- 0l. l 92. 3 0i. d 9a. 8

'l Denotes hydrocarbon constituents containing appro ximateiy the number of'carbon atoms in the molecule.

From the above it is apparent that an apprestage 1 of the respective operations. This is evident from the substantial increase in yield of .Cs constituents in stage 1 as compared to stage 2 of the respective operations. Furthermore, it is present process unexpected desirable results were secured. For example, the acid passed serially through the respective stages was of a better quality as it was removed from stagev 2 than Example 2 45 Bu lens i ma. suo nent bgle addition oi ethylene and dnm' butylena y 50 catalyst os H so s mso.. Feed Iagutne. Iso ntane.

Mol mio: Isobutayziesn co as YMoi ratio: CaHa/O 1.4 1.4 Total reaction time im 1I) 55 Time 0f feed addition 150 w Temperature 70 70 Product e: e: Vol. percent Ct i 1%111 1&2 Vol IIC -I-DMF) 7i: so reen .p'x M. o. 95.1 5.o Und ldd, turntable loidity......e... 5 23.7

' What we claim is new and wish to protect by ciable alkylation of the ethylene was secured in 25 Letters Patent is:

1. Improved alkylation process which comprises intermittently contacting under alkylatins' conditions an acid of the class consisting ot sulfuric acid and iiuorosuifonic acid with afeed stream comprising ethylene and isopar, and a :feed

stream comprising oleiins and lsoparailins free oi'- ethylene.

2. Process asdeiined by claim 1 in which the acid comprises an 88 to 100% concentrated sulphuric acid.

3. Improved alkylation process which comprises contacting an acid of the class consisting .of sul furie `acid and'iluorosulfonic acid, f

and oleilns comprising ethylene in an initial alkylation zone under alkylating conditions, segregating a portion of the emulsion removed from said initial aikyiation zone and separating the acid therefrom, contacting said separated' acid with isoparamns and oleiins tree o! ethylene in a secondary alkylation zone under alkylating conditions, segregating a portion ofthe emulsion removed from said secondary alkylation zone andl separating the acid therefrom, recycling said separated acid to said initial aikylation zone.

4. Process as deiined by claim 3 in which the acid comprises an.88% to sulphuric acid.

l ALEXIS vooRHms, Jn. ERwm M. mirroir. 

